In the related art, there is known a seat reclining device which is described in JP-A-2007-307182 (Reference 1), for example. The seat reclining device is provided with a reclining unit which is interposed between a cushion frame (a cushion-side arm) and a back frame (a back-side arm). When the seat back occupies a reclining locking range between a standing state and a maximum reclined state, it is possible to lock or unlock the reclining unit at an arbitrary angle, and when the seat back occupies a non-locking range between the standing state and a pushed-forward state, the reclining unit rotates freely. The seat reclining device is provided with an unlocking lever for switching the reclining unit from the locked state to an unlocked state. The seat reclining device is provided with a restraint lever which is connected to the unlocking lever via a long hole and a pin to restrain the rotation of the unlocking lever in the locking direction such that the seat reclining device rotates in an opposite direction from the rotational direction of the unlocking lever when the unlocking lever is caused to rotate in an unlocking direction. The seat reclining device is provided with a pressing portion which is provided on the back frame and presses the restraint lever.
In this configuration, when the seat back is pushed forward in a state in which the restraint lever occupies an unlocked position in accordance with an unlocking operation of the unlocking lever, the unlocking lever is held in the unlocked position with the restraint lever due to the pressing portion pressing the restraint lever, and the unlocking of the reclining unit is maintained continually.
Incidentally, in Reference 1, the unlocking lever is held in the unlocked position due to the pressing portion holding (pressing) the restraint lever in the pushed-forward state of the seat back. In this case, when an attempt is made to stand the seat back from the pushed-forward state, the unlocking lever is apt to rotate toward a locked position together with the restraint lever which is freed from the pressing portion. At this time, the unlocking lever is held in the unlocked position due to the pushed-forward state of the seat back occupying the non-locking range of the reclining unit. In other words, it is necessary to adopt a reclining unit in which the pushed-forward state of the seat back occupies the non-locking range, and the design freedom is impaired.